I. Field
The following description relates generally to wireless communications, and more particularly to layer 3 signalling encoding in a multicarrier wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems can include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), multi-carrier wireless specifications such as evolution data optimized (EV-DO), one or more revisions thereof, etc.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple user equipments (UEs). Each UE can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to UEs, and the reverse link (or uplink) refers to the communication link from UEs to base stations. Further, communications between UEs and base stations can be established via single-input single-output (SISO) systems, multiple-input single-output (MISO), multiple-input multiple-output (MIMO) systems, and so forth. In addition, UEs can communicate with other UEs (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
In conventional wireless communication environments, one carrier can be used for serving a UE. Thus, downlink traffic can be received by the UE and uplink traffic can be transmitted by the UE using such carrier. More recently, multicarrier operation is supported. Accordingly, a UE can be configured to support a plurality of component carriers. For example, a UE can be configured to support up to five component carriers, and the component carriers can have respective bandwidths up to 20 MHz. Following this example, the UE can be configured to support five component carriers, which can provide 100 MHz bandwidth for downlink and uplink transmissions. Yet, it is to be appreciated that the UE can be configured for fewer than five component carriers (e.g., one, two, three, or four component carriers). Moreover, configuration can be effectuated on a per UE basis.
When one carrier is used for serving a UE, a control transmission, which includes layer 2 control information specified for the UE, can be encoded and sent by a base station to the UE on the carrier. Further, the control transmission can be linked to a data transmission on the carrier. For instance, the control transmission can schedule the data transmission on the carrier. The data transmission can be an uplink data transmission or a downlink data transmission. Moreover, layer 3 control information specified for the UE for the carrier can be embedded in the data transmission sent on the carrier (e.g., embedded in the uplink data transmission or the downlink data transmission sent on the carrier, . . . ).
Moreover, when more than one component carrier is used for serving a UE in multicarrier operation, separate control transmissions can be encoded and transmitted by a base station to the UE. The separate control transmissions can be linked to data transmissions on the more than one component carrier. The separate control transmissions can include respective layer 2 control information specified for the UE for respective data transmissions. For example, if two component carriers are employed to serve the UE, then two control transmissions can be encoded and sent by the base station. Further, the two control transmissions can respectively correspond to two data transmissions. By way of illustration, a first control transmission can indicate an allocation on a first component carrier used for a first data transmission, and a second control transmission can indicate an allocation on a second component carrier used for a second data transmission. However, when a UE is configured to monitor multiple component carriers, conventional approaches for encoding and transmitting layer 3 control information can be inefficient and complex.